Antennas for synthetic bandwidth microwave imaging system

The design of four tapered slot antennas covering four channels of a novel microwave imaging system that is based on the synthetic bandwidth radar (SBR) technique is presented. The SBR technique aims to synthetise a number of antennas working separately over different sub-bands and produces an equivalent antenna with ideal performance over the entire bandwidth using a proper signal processing method. The synthetised equivalent antenna keeps the same characteristics as that of each corresponding sub-band antenna in various ranges of the operational bandwidth. Thus, the SBR technique provides the solution to bypassing the design difficulties of transducers and overcoming the dilemma caused by the near-field effect in medical imaging applications. It improves the ultra-wideband radar systems through better sensitivity, higher reliability and more flexibility in the choice of the operational bandwidth.